The invention relates to a method for allocating frequencies to base stations in a mobile telephone network, and in particular to a method for automatically resetting already allocated frequencies in the event of non-saturated base stations and reallocating frequencies to the base stations.
In conjunction with the expansion of an existing mobile telephone network, for example by adding new base stations, it may happen that several of the newly added base stations are non-saturated after a frequency has been allocated, which is typically performed with the help of EDP-supported methods. In other words, a lesser number of frequencies than required are (can be) allocated to the base stations.
There are essentially two reasons why these base stations are non-saturated after a method for allocating frequencies has been applied. On one hand, it may involve base stations which cannot reach saturation due to a combination of the network structure and the planning parameters; on the other hand, it may involve base stations which cannot receive the allocation of the desired number of frequencies that are free from interference due to earlier allocations of frequencies to “old” base stations. In the second case, there remains in principle the possibility to achieve a saturation of the base stations by retuning “old” frequency allocations, which would then allow an allocation of frequencies to the newly added stations. This second possibility has hitherto been performed manually by the mobile network planners. Manual processing not only requires that stations preventing an allocation are identified, but also requires determination of an optimal new allocation of frequencies.